Electronic display apparatuses are important in a recent information society, and the electronic display apparatuses are used in various fields. Various electronic display apparatuses have been improved to meet various demands of the information society.
An electronic display apparatus displays various pieces of information so that a user easily recognizes the information through the electronic display apparatus. That is, the electronic display apparatus converts an electronic data signal outputted from an electronic apparatus into a light data signal that is perceivable by a user's eyesight. The electronic display apparatus serves a bridge between the user and the electronic apparatus.
The electronic display apparatuses are generally divided into an emissive display apparatus and a non-emissive display apparatus. The emissive display apparatus displays a light data signal utilizing a light luminescence mechanism, while the non-emissive display apparatus displays a light data signal employing light modulation mechanism such as reflection mechanism, diffusion mechanism, interference mechanism, etc. The emissive display apparatus, called as an active luminescent apparatus, includes a cathode ray tube (CRT), a plasma display panel (PDP), a light emitting diode (LED) and an electro luminescent display (ELD). The non-emissive display apparatus, called as a passive luminescent apparatus, includes an LCD, an electrochemical display (ECD) and an electrophoretic image display (EPID) apparatus.
The CRT is used in a television receiver set or a monitor for a computer. Although the CRT has high display quality and low cost, the CRT has heavy weight, large volume and large power consumption.
Electronic apparatus has been improved to have compact and small dimension, light weight and lower power consumption in accordance with the rapid improvement of semiconductor technology.
The LCD apparatus has some advantages such as a thinner thickness and a lighter weight than other flat display apparatuses, and also the LCD apparatus operates with low power consumption and low driving voltage. In addition, the LCD apparatus has high display quality and low manufacturing cost so that the LCD apparatus has been widely used in various fields.
The LCD apparatus may be easily manufactured using a proper photoresist composition for forming a photoresist film that determines the yield of a microcircuit. A quality of the microcircuit manufactured by an etching process is directly affected by the sensitivity, the developing contrast, the resolution, the adhesiveness to a substrate and the remnant characteristics of the photoresist film.
In order to form a pattern according to a conventional method, a photoresist film including organic material is formed on a substrate including an insulation film or a conductive film formed thereon. When the photoresist film formed on the substrate is exposed by ultraviolet or X ray, the solubility of the photoresist film against alkali solution is changed. When the photoresist film is exposed using a mask, a predetermined portion of the photoresist film is exposed. When the exposed portion of the photoresist film is developed, the portion of the photoresist film having relatively larger solubility is removed to thereby form a photoresist pattern exposing the portion of the insulation film or the conductive film. The exposed portion of the insulation film or the conductive film is etched to form an insulation film pattern or a conductive pattern on the substrate. The remaining photoresist pattern is then removed using an ashing or a stripping process. Thus, the insulation film pattern or the conductive pattern serving a wiring or an electrode is formed on the substrate.
There is disclosed one conventional photoresist composition including a novolak of cresol-formaldehyde and photosensitive material substituted by naphthoquinonediazide in U.S. Pat. Nos. 3,046,118, 4,115,128, 4,173,470 or Japanese Laid Open Publication No. 62-28457. Additionally, there is provided another conventional photoresist composition having soluble alkali resin, o-naphthoquinonediazide sulfonic ester and vinyl ether compound in U.S. Pat. No. 5,648,194. Further, still another conventional photoresist composition including soluble alkali resin and formed using quinonediazide compound and polymer of polyphenol is disclosed in U.S. Pat. No. 5,468,590. Still another conventional photoresist composition of improved characteristics having novolak, quinonediazide and polyphenol is disclosed in U.S. Pat. No. 5,413,895.
After the insulation or the conductive pattern is formed on the substrate, the photoresist pattern is removed using a stripping composition including an organic solvent or an alkali solution. The organic solvent is widely employed since it efficiently removes the photoresist pattern while it does not erode the pattern or the substrate. However, the organic solvent is expensive as well as the organic solvent may cause a serious pollution.